Is it possible to preview EXR or HDR files in Pantheon Files, thumbnails? It works great with KDE Neon and Dolphin.
I had a somewhat similar question before: File that handles raw thumbnails in Files, but I didn't get a useful answer.
I was considering a Sigma camera and I wanted the camera raw thumbnails in pantheon-files, but I've changed my mind about the Sigma anyway.
The only editable thumbnails files I could find were
/usr/share/thumbnailers/evince.thumbnailer. You can try those, but they didn't work for me.
Another workaround is installing Nautilus, then create the file
/usr/share/thumbnailers/raw.thumbnailer and add the
mimetype for the HDR files in it. I'll give you details about it, if you want.